When I refer to bonded pairs, I am referring to their long promised and allegedly(atleast in DFW) soon to be available bandwidth update, with 24/3 going to 30/3 and a higher 45/5 offered. With later updates(with the us of vectoring) to 75/10. All while most of their competitors already offer over 100+/15+ and can expand with even faster speeds, while AT&T is going to max out their capabilities on their copper last mile at about ~100/25 if they ever even get that far.
As for being cheaper its marginally cheaper than FIOS, but fios is way faster 75/35 vs 24/3, and that is not taking into account Uverse's IPTV bandwidth usage which can drop 24/3 to as low as 6mbps. That said if you also have AT&T wireless Uverse can be substantially cheaper.